Weatherproof air conditioning disconnect switch

ABSTRACT

A weather-tight air conditioning disconnect switch has both plastic and metal enclosure components for low cost assembly. The exterior components include a metal case and cover whereas the interior non-electrical components are plastic-molded. One such molded plastic dead-front shields the electrical terminals within the enclosure and contains instruction and caution indicia integrally-formed on the exterior surface during the plastic molding forming process. ON - OFF indication of the switch is achieved by the orientation of the switch handle with the switch handle receiver.

BACKGROUND OF THE INVENTION

U.S. Pat. No. 4,675,782 entitled "Molded Plastic Enclosure forDisconnect Switches" describes a three-component molded plasticenclosure wherein the electric insulation to the electric fuses andother metallic plastic components multi-functionally provide support andelectric insulation to the electric fuses and other metallic electricalcomponents contained therein. When such a disconnect switch is usedwithin air conditioning units, for example, a repair person working onthe air conditioner unit must be assured that the switch remains in the"OFF" position until such work is completed. The "ON and OFF" indiciaare located on opposite sides of the removable handle-connector assemblyso that the "OFF-ON" condition of the switch can be confirmed byvisually observing the "ON and OFF" indicia. In order for the operatinghandle to remain visible from the exterior of the enclosure, the door isprovided with a special "Hibbert" hinge that is, a hinge that allows thedoor to remain open when the door is rotated past its fully openedposition.

For some non-fused applications, a less expensive disconnect switch notrequiring three separate enclosure components can be employed.

One such arrangement is found within U.S. Pat. No. application Ser. No.100,506 entitled "Loop-Feed Wiring Arrangement For Electric CircuitBreakers and Switches" wherein both plastic and metal enclosurecomponents are employed. This Application also describes a means forwiring the line and load connections from the same direction forimproved safety as well as economy.

Both the aforementioned U.S. Patent and Patent Application areincorporated herein for reference purposes and should be reviewed forthe advanced state of the art of disconnect switch interior componentconfigurations and exterior enclosure construction and design.

One purpose of the instant invention is to provide a simple andinexpensive disconnect switch that employs a two-component metal-formedexterior enclosure that does not require any bolts or other fasteningcomponents and which incorporates plastic interior components forshielding, support and electrical isolation functions.

BRIEF DESCRIPTION OF THE INVENTION

The invention comprises an electric disconnect switch contained within atwo-component enclosure consisting of a metal cover and a metal casewherein the cover cooperates with means integrally-formed within thecase to hold the cover in an open position. A plastic dead-front shieldinteracts with the interior plastic pullout switch assembly and containsindicia describing the switch operating parameters and caution notices.Means are integrally-formed on the pullout switch assembly for visuallyindicating the switch "ON" and "ON" conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view in isometric projection of the interiorcomponents used within the disconnect switch according to the invention;

FIG. 2 is a top perspective view of the disconnect switch according tothe invention with the plastic shield in isometric projection;

FIG. 3 is a plan view of the assembled interior components of thedisconnect switch according to the invention;

FIG. 4 is a top perspective view of the exterior enclosure cover andcase according to the invention with the cover arranged in isometricprojection; and

FIGS. 5A-5D are cutaway side views of a part of the exterior componentsof FIG. 4 detailing the lockopen features of the cover.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The pullout switch assembly components 10 are shown in FIG. 1 andinclude an insulative plastic base 11 with means formed therein forsupporting a pair of load terminal lugs 12, 13 and line terminal lugs14, 15. The line terminal lugs are mechanically and electricallyconnected to a corresponding pair of line stabs 16, 17 and load stabs18, 19 as indicated. The base also includes "active" recesses 20, 21 and"passive" recesses 22, 23 which will be discussed below in greaterdetail. It is suffice to note that both the line and load stabs arearranged within the active recesses. An insulative plastic guide 24 isnext positioned over the base and is attached to the metallic case 39(FIGS. 2, 4) by means of thru-holes 28, arranged on opposite sides ofthe case and by means of machine screws 28A. A longitudinal channel 25formed within the guide provides access to the line and load stabs forreceiving corresponding slotted blades 30, 31 which are attached to thehandle 29 within corresponding recesses 34, 35 integrally-formed thereinand attached thereto by means of screws 32, 33. Formed within theopposing ends of the guide are a pair of slots 26, 27 which cooperatewith an indicating tab 38 formed on the handle in a manner to bedescribed below in greater detail. The indicating tab 28 isintegrally-formed within the planar surface 37 which extends upwards toand terminates in a T-shaped grip 36 to facilitate operating the handle.

The interior pullout switch assembly components 10 are now depicted inFIG. 2 attached to the bottom 45 of the metallic case 39. Also attachedto the bottom of the case, is the neutral assembly 46 which includes apair of neutral terminal screws 48. The neutral terminal assembly ismechanically attached and electrically bonded to the case by means of amachine screw 47. The case is formed from a single piece of sheet metalwhich is shaped into a pair of upstanding sides 43-44, a front 41 and arear 42. A plurality of knockouts 49 are cut within the front, bottomand sides as indicated. These knockouts allow for wiring access to theline and load terminals contained within the pullout switch assembly. Aseparate metal cover 40 is formed from a single piece of sheet metalinto opposing sides 54, 55 interconnected by a front 53. An oval recess52 is integrally-formed within the cover to provide clearance for theupstanding T-shaped grip 36. An insulative plastic dead-front or shield56 is arranged over the electrical components on the pullout switchassembly by positioning the pair of recesses 58, 59, formed on theshield, under a corresponding pair of tabs 62, 63, formed on the guide24, and overlaying the platform 57, formed on the shield, onto thepedestal 61. The opposite end of the shield rests on the tabs 51 whichis formed within the front 41 of the case. The shield is fastened to thecase by means of a thru-hole 60 formed within the shield and a threadedhole 51A through the tab. A padlock hasp 50 formed on the front of thecase includes a circular protrusion 50A which moves the hasp out of thepath of the front 53 of the cover 40 when the cover is being closed andthe hasp traverses through the elongated slot 88 formed through thecover.

The pullout switch assembly 10 is depicted in FIG. 3 with the loadterminal lugs 12, 23 and the line terminal lugs 14, 15 attached tocorresponding load stabs 18, 19 and line stabs 16, 17 within theirrespective active recesses 20, 21. Insulative plastic barriers 65-70 areintegrally-formed with the base 11. The barriers 67, 68 proximate theload terminal lugs 12, 13 are marked with the word "Load" while thebarriers 65, 70 proximate the line terminal lugs 14, 15 are accordinglymarked "Line". The "Line" and "Load" indicia are formed integral withthe forming of the base components and are permanently affixed therein.Corresponding "OFF" indicia is integrally-formed within the slot 26 and"ON" indicia is formed within the opposite slot 27, as indicated. It isnoted that the passive recesses 22, 23 contain no electrical components.To provide a clear indication of the condition of the slotted blades 30,3 of FIG. 1 with respect to the line and load stabs 16-7, 18-19, theindicating tab 38 on the handle 29 shown in FIG. 1 interacts with theslots 26, 27 in the following manner. When the handle 29 is in its "ON"condition, the slotted blades 30, 31 are inserted within the activerecesses 20, 21, and electrical connection is made between the adjacentline and load stabs 16, 18 and 17, 19. The indicating tab 38 nestswithin slot 26 to thereby obliterate the "OFF" indicia contained thereinsuch that the "ON" indicia contained within the opposite

27 is readily visible. In like manner, when the. handle 29 is in its"OFF" condition such that the slotted blades 30, 31 are positionedwithin the passive recesses 22, 23, the indicating tab 38 obliteratesthe "ON" indicia in slot 27 such that the "OFF" indicia within slot 26is readily visible. Recess 64A formed in the bottom 24A of the guide 24receives the projection 64 formed on the handle 29 to guide theinsertion of the grooved blades 30, 31 within the passive recesses 22,23.

The assembly of the cover 40 to the case 39 is best seen by referringnow to FIG. 4 wherein the cover 40 is punched from a single piece ofsheet metal and is formed into opposing cover sides 54, 55 and front 53.A pair of elongated slots 83, 84 are formed within the ends of the coversides opposite the front 53. A slot 85 formed in the front 53 of thecover 40 allows for clearance of the cover with respect to the knockouts49 formed on the front 41 of the case 39 and a pair of slots 86, 87formed on the sides 54, 55 of the cover allow for clearance of the coverwith respect to the knockouts formed on the sides 43, 44 of the case.This results in the use of less material for the front and sides of thecover and hence to reduced material costs. The case 39 is shaped from asingle piece of sheet metal into opposing sides 43, 44 to which thefront 41 is welded by means of angled ends 71, 72. The end of the casesides opposite the front, are truncated as indicated at 73, 74 and apair of slots 75, 76 are formed at the truncated ends. A pair of tabs77, 78 are punched within the case sides and extend outboard thereof andare captured within the slots 83, 84 to pivotally attach the cover tothe case. The flaps 81, 82 extending from the ends of the rear 42, arefolded over and welded to complete the box-like configuration depictedin FIG. 2. The cover 40 is snapped onto the case 39 and the pair ofcircular protrusions 79 and 80, formed near the truncated ends, act asguides and stops for the cover as the cover is rotated between its openand closed positions as well as providing welding surfaces for weldingthe flaps.

One of the important features of the invention is the retention of thecover in its open position, such as indicated in FIG. 2, so that theposition of the T-shaped grip 36 and the location of the indicating tab38 is clearly visible. As described earlier, the position of theindicating tab portrays the ON - OFF condition of the switch. To ensurethat the cover remains in its open position, the cover interacts withthe case as best seen by now referring to FIGS. 5A-5D.

In FIG. 5A, wherein only one cover side 54 and flap 81 is visible priorto folding over. The end 54 of the cover side abuts the bottom of theslot 75 formed within the truncated end 73 of the case side 43. The tab77 formed within the case abuts the top edge of the slot 83 formedwithin the cover such that the cover side is now positioned between theslot 75 and The circular protrusion 79. To rotate the cover to itsclosed position, the cover is moved forward such that the end 54A islifted out from slot 75 and the tab 77 now abuts the bottom of slot 83as shown in FIG. 5B. Rotating the cover in a clockwise direction abouttab 7/ allows the cover to reach the position indicated in FIG. 5C suchthat the cover side 54 stops against the protrusion 79 with the tab 77abutting the bottom of slot 83. To move the cover to its fully closedposition, the cover is slid in the indicated direction along the top ofthe protrusion 79 until the tab 77 abuts the top edge of slot 83 asshown in FIG. 5D.

An inexpensive disconnect switch has been described herein consisting ofa metal cover and case which form a weather-tight enclosure for theinterior pullout switch assembly components. The pullout switch assemblycomponents include a plastic base and guide which carry indicia toidentify the line and load terminals as well as to indicate the "ON" and"OFF" condition of the switch. The cover interacts with the case toremain in an open condition such that the interior switch components areclearly visible.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:
 1. An electric disconnect switchcomprising:a metal cover and a metal case .Iadd.said cover attached tosaid case.Iaddend.; a molded plastic base attached to a bottom surfaceof said: case; a molded plastic handle guide positioned over said base,said base including a plurality of line and load stabs arranged under achannel formed in said handle guide; .[.and.]. a molded plastic handleassembly including a shaped handle grip projecting from one end and aplurality of line and load blades extending from an opposite endthereof, said handle assembly being slidably arranged within said handleguide whereby said line and load blades are moved into and out ofcontact with said line and load stabs by operation of said handlegrip.Iadd.; and a planar insulative shield attached to said case andarranged over said line and load stabs to prevent inadvertent contactwith said line and load stabs when said switch is electricallyenergized.Iaddend.. .[.
 2. The electric disconnect switch of claim 1including a planar shield attached to said case bottom surface andarranged over said line and load stabs to prevent inadvertent contactwith said line and load stabs when said switch is electricallyenergized..].
 3. .[.The electric disconnect switch of claim 2 wherein.]..Iadd.An electric disconnect switch comprising:a metal cover and a metalcase said cover attached to said case; a molded plastic base attached toa bottom surface of said case; a molded plastic handle guide positionedover said base, said base including a plurality of line and load stabsarranged under a channel formed in said handle guide; a molded plastichandle assembly including a shaped handle grip projecting from one endand a plurality of line and load blades extending from an opposite endthereof, said handle assembly being slidably arranged within said handleguide whereby said line and load blades are moved into and out ofcontact with said line and load stabs by operation of said handle grip;and a planar insulative shield attached to said case and arranged oversaid line and load stabs to prevent inadvertent contact with said lineand load stabs when said switch is electrically energized .Iaddend.saidhandle guide includes a pair of tabs extending from a top surfacethereof and said shield includes a corresponding pair of recesses formedat opposite ends, said tabs being arranged within said .[.recesses.]..Iadd.recesses .Iaddend.supporting one end of said shield on said base.4. The electric disconnect switch of claim 3 further including apedestal integrally-formed on said handle guide receiving a platform onsaid shield intermediate said recesses.
 5. The electric disconnectswitch of claim .[.2.]. .Iadd.1 .Iaddend.including .[.a pair of slotsformed on.]. a top surface of each side of said handle guide and anindicating tab extending from one side of said handle assembly whereby"ON - OFF" indicia .[.within said slots.]. .Iadd.on said top surface.Iaddend.become selectively covered and exposed by said indicating tabto display the relationship between said line and load stabs and saidblades.
 6. The electric disconnect switch of claim 1 includingupstanding barriers integrally-formed between said line and load stabs,each of said barriers containing indicia formed on a top surface toidentify adjacent ones of said line and load stabs.
 7. The electricdisconnect switch of claim .[.2.]. .Iadd.1 .Iaddend.wherein said casecomprises a single metal plate formed into a bottom piece having anupstanding front piece, upstanding rear piece and a pair of opposingupstanding side pieces.
 8. The electric disconnect switch of claim 7wherein said cover comprises a single metal plate formed into a planartop piece having a depending front piece and a pair of opposingdepending said pieces.
 9. The electric switch of claim 8 wherein each ofsaid case side pieces includes a .Iadd.side piece .Iaddend.slot formedtherein extending in a plane coextensive with said case side pieces andwherein said cover side pieces are retained within said .Iadd.side piece.Iaddend.slots when said cover is in an open position.
 10. The electricdisconnect switch of claim 9 wherein each of said case side piecesinclude a pair of .Iadd.side piece .Iaddend.tabs projecting outboardtherefrom and each of said cover side pieces include a pair of elongated.Iadd.cover .Iaddend.slots from therein, said .Iadd.side piece.Iaddend.tabs being captured within said elongated cover slots therebyslidingly retaining said cover to said case.
 11. The electric disconnectswitch of claim 10 including a pair of circular protrusions formed onsaid case side pieces proximate and .Iadd.side piece .Iaddend.tabs.[.and providing guide means supporting said cover when said cover ismoved from an open to a closed position.]..
 12. The electric disconnectswitch of claim 11 including a slotted hasp formed in said case frontpiece providing attachment means for a padlock.
 13. The electricdisconnect switch of claim 12 including a .Iadd.top piece .Iaddend.slotformed within said cover top peices said .Iadd.top piece .Iaddend.slotcapturing said slotted hasp when said .Iadd.cover .Iaddend.is in saidclosed position.
 14. The electric disconnect switch of claim 13including an angled tab formed on said case from piece and receiving anopposite end of said shield.
 15. The electric disconnect switch of claim12 wherein said slotted hasp includes a protrusion for interacting witha cover slot to move said slotted hasp away from said slot when saidslot captures said slotted hasp. .Iadd.
 16. An electric disconnectswitch comprising:a metal cover and a metal case said cover attached tosaid case; a molded plastic base attached to a bottom surface of saidcase; a molded plastic handle guide positioned over said base, said baseincluding a plurality of line and load stabs arranged under a channelformed in said handle guide; a molded plastic handle assembly includinga shaped handle grip projecting from one end and a plurality of line andload blades extending from an opposite end thereof, said handle assemblybeing slidably arranged within said handle guide whereby said line andload blades are moved into and out of contact with said line and loadstabs by operation of said handle grip; a molded plastic shield attachedto said case and arranged over said line and load stabs to preventinadvertent contact with said line and load stabs when said switch iselectrically energized, said plastic shield containing instruction andcaution indicia integrally-formed on an exterior surface thereof..Iaddend.